This is a continuation-in-part of application Ser. No. 059,745, filed Jun. 8, 1987, now U.S. Pat. No. 4,843,742, issued Jul. 4, 1989.
This invention relates to trenching or trench excavating apparatus wherein a deep trench is dug and corners are formed, the trench to receive poured concrete as in the formation of an inground retaining wall. It is contemplated that the trench dug by the apparatus will have a depth of up to or exceeding 25 feet.
A propulsion apparatus which is engageable with the side or base walls of a trench is disclosed in co-pending application Ser. No. 059,745, and may be utilised to provide propulsive force within the trench, enabling a relatively light machine to be used for a particular trenching operation. Such propulsion apparatus may have difficulty adapting to varying ground types and may jam due to the ingress of dirt dislodged during the excavation process, or wet concrete, which is often poured immediately behind the trenching arm to minimize the probability of trench collapse in soft ground conditions.